Physicochemical Properties and Bioactive Compounds of Coffee Extracts Prepared by Partial Substitution with Wheat and Barley Grass

Abstract

In this study, mixtures of coffee and cereal grass were prepared by substituting ordinary roasted coffee with cereal grass (wheat and barley grass) at concentrations between 5∼15%. The physicochemical properties and bioactive compounds of the extracts were subsequently evaluated. We observed that increasing concentrations of cereal grass (5∼15%) resulted in increased levels of crude protein content and decreased crude fat and ash contents of the mixture samples. Increase in the lightness of coffee extract was proportional to the increase in cereal grass, whereas the redness, yellowness, and browning index were decreased. With an increase in the ratio of cereal grass, the total phenolic content decreased slightly, while the flavonoid content tended to increase. The chlorophyll, β-carotene, and vitamin C contents increased in the coffee extract containing higher concentrations of cereal grass. No significant difference was obtained in the DPPH radical scavenging activity with increased cereal grass concentrations, but the SOD-like activity was observed to increase. Taken together, our results indicate that partial supplementation of coffee with wheat or barley grass has the potential to increase bioactive compounds and enhance the function of caffeinated coffee drinks. © 2023 The Korean Society of Food Science and Nutrition.